Dimensional lumber has long been used in the construction of outdoor structures, to include decks attached to homes, or docks used for access to watercraft, for example. Dimensional lumber offers the advantage of relatively low cost, and it can be quickly and easily cut to size and joined together to form the desired structure. However, a significant disadvantage when using dimensional lumber in outdoor applications, even if the lumber is pressure treated. is the fact that the lumber is exposed to the elements, and over time the lumber will inevitably begin to crack, split, fade, and splinter. This problem can be overcome by painting or staining the exposed surfaces of the lumber and by performing periodic maintenance on the structure, but this becomes a time consuming and expensive ordeal as the lumber weathers over time. Also, lumber is significantly affected by ambient weather conditions, primarily heat and moisture, so that the lumber tends to warp or twist over time.
In the effort to combat these known problems with the use of dimensional lumber in constructing decks and docks, the use of extruded structural components has been developed. These extrusions may be either of a plastic or a metallic material for example, aluminum, or the decking planks may even be comprised of a plastic resin, as was done in U.S. Pat. No. 4,349,297 to Misener. Common examples of extruded decking/docking systems are disclosed in U.S. Pat. Nos. 4,947,595 to Douds, et al., disclosing an extruded metal plank for use in the construction of deck surfaces; 5,009,045, and 5,048,448 to Yoder, disclosing a plank structure for a boat dock and the like, as well as a boat dock structure, respectively; and, more recently, in U.S. Pat. No. 5,613,339 to Pollock, which discloses a decking system using two different extrusions of two different constructions which, when joined together, form an elongate deck plank.
Although the aforementioned patents provided deck planks, or dock structures which address the problems of dimensional lumber, problems still persist with the use of this type of extruded decking. For example, in the patent to Douds, et al., the extruded metal plank most closely resembles decking used in industrial applications, and does not appear to be particularly well-suited for use in residential applications, for example the construction of home decks and docks, due to cost considerations coupled with the fact that exposed flanges are left as a part of the deck extrusion which might lead to accidental injury. Also, as the extrusion of Douds, et al. is made of metal, it may tend to burn the feet of people walking barefoot on a sun exposed deck, as would commonly occur on non-commercial decks or docks, and may be relatively slippery when wet.
Similarly, the '448 patent to Yoder discloses a plank structure for a boat dock which has the disadvantage that a first extruded plastic strip of a first design must be secured to the frame of the deck or dock structure, the strip having a number of protrusions formed therein for receiving the plank structure of the '045 Yoder patent, which thus necessitates that these spaced and opposed strips be precisely aligned with one another during construction of the deck/dock, which, as any person of ordinary skill in the construction arts is aware, becomes a difficult task in the field. Thereafter, an extrusion of a second different construction, the extruded "plank" of the '045 patent, must be positioned over the spaced, parallel, and aligned extrusions disclosed in the '448 Yoder patent, and then fastened thereto.
Similarly, the patent to Pollock discloses a first extrusion which must be placed on the support structure of the deck or dock and fastened thereto, whereupon a second, different extrusion is positioned on top of the first extrusion, and snapped into place to form the deck plank. Moreover, Pollock teaches that these two extrusions are formed of two different plastics, the second or surface extrusion being made of a more pliable material. Similarly, the '045 Yoder patent also discloses the use of two differing plastic materials to extrude the second of the two decking system extrusions used.
Although the patents to Yoder and Pollock offer the advantage of a plastic material, which is well suited for use in residential applications, these patents have the disadvantage that two differing extrusions are used which must be "joined" together to form the deck or dock structure during construction in the field. This necessitates that two different extrusions be manufactured, at significant expense as this impacts the costs of designing and tooling the differing extrusion dies to be used, as well as increasing material costs in that an inventory of two different extrusions must be maintained in order to be able to sell the boat dock structure, or deck plank of the Yoder and Pollock patents, respectively.
One-piece metallic extrusions have been developed which have been constructed and arranged to be fastened to one another in a 180.degree. reverse relationship to form an elongate structural member. Examples of such extrusions are disclosed in U.S. Pat. Nos. 3,282,005 to Birdwell; 4,987,717 to Dameron, Jr.; and 5,031,083 to Claesson. These extrusions, however, appear to be poorly suited for use as load bearing structural components in deck and dock applications, and instead appear to be specialty extrusions. For example, the extrusion of Birdwell is a single one-piece extrusion which is placed in a 180.degree. reverse relationship by sliding the two extrusions together, along their length and end first, to loosely mate them together, whereupon the two extrusions are then tack-welded to hold them in position relative to one another, in conjunction with spacer shims placed between the two extrusions so that the extrusion is loosely formed as a structural box beam. Thereafter, the extrusion is then fastened to a building, for example a building facade, as a decorative and not a load-bearing component by placing spaced fasteners through the slot between the two extrusions to complete the "formation" of the box beam.
Similarly, the extrusion of Dameron, Jr. appears also to be used for decorative and/or non load-bearing purposes, only, although it may also be used as used as a gutter facade, i.e. as a gutter, along the roof line of a residential or commercial structure. The extrusion of Dameron, Jr. may also be used as a box beam, however, but apparently only as a decorative facia or other non-load bearing structural/aesthetic component. The extrusions of Dameron, Jr., as well as the extrusion to Birdwell, are mated by sliding two identical extrusions together, ends first and along their length, once placed in an overlying 180.degree. reverse relationship with respect to one another, to form the extrusions into a box beam. Moreover, the extrusion of Dameron, Jr. would not be useful as a deck or dock component because it appears to be much too fragile to carry or support a load along its length, and its method of assembly is highly impractical for decks/docks because it would require workers to be positioned on ladders outside or off of the structural support framework of the deck or dock, to include even standing in, or floating on water, for example, in order to slide the two extrusions together to form the box beam once a first of the extrusions is fastened to the support framework. This is extremely unworkable in that the construction of decks and docks requires not only speed and efficiency, but safety as well when constructing the structure.
The extrusion of Claesson is used for creating cable runs in which electrical cables, for example, are housed. The extrusion of Claesson, however, also makes provision for the placement of light-emitting diodes, or other light-emitting devices thereon, so that two extrusions, when placed together, form an elongate "box beam" which can apparently be used for decorative purposes also. The extrusion of Claesson, however, offers the disadvantages that it does not have a uniform cross-section which thus leads to differential cooling during the extrusion process as well as leading to uneven material flow through the extrusion die, all of which tends to cause twisting and warping within the extrusion, which must be minimized to the greatest extent possible during the manufacturing process for maximizing production efficiency and minimizing production costs by minimizing waste or spoilage. Moreover, the profile of Claesson results in overlapped side joints, which complicates assembly by requiring careful joining of the two profiles, as well as increased weight, and thus material costs, in the construction of the "profile."
What is needed, therefore, is a one-piece extrusion which can be used to construct an elongate deck plank, and which can be easily and quickly installed in the field for constructing the deck or dock with which the extrusion is being used. What is also needed, but seemingly unavailable in the art, is the provision of a one-piece extrusion which can accomplish this task, yet which can be manufactured of recycled plastic for the purposes of reducing manufacturing costs, and also for benefiting the environment by recycling waste plastics commonly used in consumer and commercial applications and supplies of which are readily available. An additional need is for a one-piece extrusion which will not require a second extrusion which must first be placed in position, and to which a second different extrusion must be fit in order to construct a deck or dock, as well as minimizing both manufacturers', distributors', and contractors' inventory by requiring that only a single style of a one-piece extrusion be maintained in inventory, as opposed to differing extrusions of differing design. Moreover, there is a need for such an extrusion which can be made of either a virgin or recycled plastic, or even a combination of the two.